From the Document: "Some military families discovered that they owed higher taxes for 2018 and 2019 on distributions from their military survivors' benefits than they had in previous years. This change in tax treatment was related to temporary changes to the 'kiddie tax' in the 2017 tax revision (P.L. 115-97). However, Congress enacted language in the Further Consolidated Appropriations Act, 2020 (P.L. 116-94) that repealed those temporary changes to the kiddie tax beginning in 2020. In addition, P.L. 116-94 enables taxpayers to retroactively elect to be taxed as if the kiddie tax changes in P.L. 115-97 did not apply in 2018 and 2019 (by filing an amended tax return)."
CRS Insight, IN11112
Congressional Research Service: https://crsreports.congress.gov/